I am absolutely venting emotionally, I thought that much was clear. :) But I heard a variant of this in dozens or hundreds of meetings, generally when a project was getting shut down or canned or reorg'd, so it's not true to say that it's not true.
It's not even a bad slogan. Company priorities should come before territorial interests. This is why it's important to work in a place that shares your values at a high level.
I think people are juxtaposing "what's good for Facebook" not with "what's good for [territorial subunit]", but rather with "what's good for the lives of the people working at Facebook." A slogan like that is sensible in the first case and terrifying in the second case.
I think you're right, and I completely intended it in a practical, non-incendiary way. People would constantly say they weren't there to pursue personal, political agendas, they wanted to have maximum impact and do what was best for Facebook. It's like the #1 catchphrase you have to memorize to get ahead. It makes sense. In most cases, it's even true.
I may have a separate set of issues with Facebook People policies, but there are a ton of really passionate, amazing engineers working there who deeply believe in the mission (or at least their local specialty). I miss many of them very much and wish them all well.